xref: /openbmc/linux/arch/arm64/include/asm/efi.h (revision 781095f903f398148cd0b646d3984234a715f29e)
1 #ifndef _ASM_EFI_H
2 #define _ASM_EFI_H
3 
4 #include <asm/io.h>
5 #include <asm/mmu_context.h>
6 #include <asm/neon.h>
7 #include <asm/tlbflush.h>
8 
9 #ifdef CONFIG_EFI
10 extern void efi_init(void);
11 #else
12 #define efi_init()
13 #endif
14 
15 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
16 
17 #define efi_call_virt(f, ...)						\
18 ({									\
19 	efi_##f##_t *__f;						\
20 	efi_status_t __s;						\
21 									\
22 	kernel_neon_begin();						\
23 	efi_virtmap_load();						\
24 	__f = efi.systab->runtime->f;					\
25 	__s = __f(__VA_ARGS__);						\
26 	efi_virtmap_unload();						\
27 	kernel_neon_end();						\
28 	__s;								\
29 })
30 
31 #define __efi_call_virt(f, ...)						\
32 ({									\
33 	efi_##f##_t *__f;						\
34 									\
35 	kernel_neon_begin();						\
36 	efi_virtmap_load();						\
37 	__f = efi.systab->runtime->f;					\
38 	__f(__VA_ARGS__);						\
39 	efi_virtmap_unload();						\
40 	kernel_neon_end();						\
41 })
42 
43 /* arch specific definitions used by the stub code */
44 
45 /*
46  * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
47  * start of kernel and may not cross a 2MiB boundary. We set alignment to
48  * 2MiB so we know it won't cross a 2MiB boundary.
49  */
50 #define EFI_FDT_ALIGN	SZ_2M   /* used by allocate_new_fdt_and_exit_boot() */
51 #define MAX_FDT_OFFSET	SZ_512M
52 
53 #define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__)
54 
55 #define EFI_ALLOC_ALIGN		SZ_64K
56 
57 /*
58  * On ARM systems, virtually remapped UEFI runtime services are set up in two
59  * distinct stages:
60  * - The stub retrieves the final version of the memory map from UEFI, populates
61  *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
62  *   service to communicate the new mapping to the firmware (Note that the new
63  *   mapping is not live at this time)
64  * - During an early initcall(), the EFI system table is permanently remapped
65  *   and the virtual remapping of the UEFI Runtime Services regions is loaded
66  *   into a private set of page tables. If this all succeeds, the Runtime
67  *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
68  */
69 
70 static inline void efi_set_pgd(struct mm_struct *mm)
71 {
72 	switch_mm(NULL, mm, NULL);
73 }
74 
75 void efi_virtmap_load(void);
76 void efi_virtmap_unload(void);
77 
78 #endif /* _ASM_EFI_H */
79